Process for the preparation of dyestuffs



i Patented' a. 1 6.1923.

UNITED STATES t Y 1 KAB-DL DzIEwoiIsKI,

A NT .OFFJIJCEI on cnAoow, PoLAmi'.

rnocnss rams-E PREPARATION or DYES'IUFFS.

No Drawing.

15. by treating the same under different conditions with ordinary or fuming sulphuric acid. Besides thb principal reaction, i. e., the sulphonation complicated secondary react-ions accompanied by oxidation take place the products of which have proved as excellent acid dyestufi's or direct sulphurdyestufi's. In this manner I found the surprising andunexpected fact, that the compounds formed, being highly coloured but possessin no autochromic groups are changed y the action of sulphuric acid into beautiful, direct and fast dyestuffs.

" Ewample.

In 10 parts of dinaplithylenethiophene are heated with 40 parts of concentrated and 2 parts of fuming (20%) sulphuric acid up to 100110 C. for 8 hours. The reaction takes place with the liberation of large quantities of sulphur dioxide, the formation of three different products taking place, viz-an amorphous violet-black compound insoluble in water and two red or brown coloured sulphuric acids of dinaphthylenethiophene respectively, which are differentiated by the solubility of their barium and calcium salts. The sulphonated mixture is diluted with water and the .sulpho-acids soluble ,in water are separated by filtration from the insoluble product of reaction. The reddish brown coloured filtrate is treated with milk of lime or barium carbonate ;until it showsa neutral reaction, whereupon the calcium sulphate mixed with the little soluble salt of the'other product of the sulphonation. is filtereil from the brownish red solution of the easi can e recovered by concentrating'the solu Application filed March 3, 1921. Serial No. 449,590. I

soluble calcium salt. The soluble salt 4 tion and boiling down to dryness. lt't'orms a Bordeaux-red crystalline substance, being according .to its composition the salt of a.

trisulphonic acid of oxydinaphthylen'ethiophene and dyes wool in an acid bath scarlet or orange red.

The other calcium salt wlrich is. diflicultly soluble in water and has. been precipitated along with calcium sulphate can be brought into solution by extracting the precipitate With a. dilute solution of'sodiuin carbonate, 7

,beingthereby converted in its sodium salts. In its dry state it form a dark brown amora phous powder, that gives wool a reddish.

brown colour. That product, a polysulphopolyoxy derivative ofdinaphthylen'etliiophene is nearly exclusively formed by sulphon'ating at a higher temperature than 100"v or with fuminv sulphuric acid.

The black-violet substance which. is little soluble in water and caustic all raline solutions an d is formed on sulphonating dinaphthylenethiophene along with the two other sulphonic acids, is. soluble in a solution ofsodium sulphide with a reddish violet colour..

That solution dyes unmordanted cotton grey-violet and is employed as a direct sul-' phur dyestufl'. I I What I claim is 1 1. A process for the preparationof dyestufl's, consisting in treating dinaphthylenethiophene with sulphuric acid.

2. -A process for the preparation of dye stuffs, consisting in heating. 10 parts of dinaphthylenethiophene with 40 parts of concentrated and twoparts of fum1ng sulphuric acid for 8 hours, dilutmg the sulphonated mixture in water, separating by filtration the sulpho-acids soluble in water from the I insoluble products of reaction, neutralizing the reddish-brown product with milk of lime, separating by the filtration the soluble calcium salt from the insoluble caly cium salt, concentrating the solutlon and l,

boilin down to dryness. J 3. 1% process for the preparation of dye- ,stufl's, consisting in heatin 10 parts of "dinaphthylenetlnophene wit 40 parts of concentrated and two parts of fuming sulphuric acid for 8 hours, diluting the sulphonated mixture in water, separating by filtration the sulpho-acids soluble in water vfrom the insoluble products of reactlon,

neutralizing the reddish-brown product with In testimony whereof I have signed my, milk of lime, separating by the filtration the name to this specification. soluble calcium salt from the insoluble cal- 1 7 l0 cium salt, extracting the precipitated (lifli- KAROL DZIEWONSIXI' E5 cult-1y soluble calcium salt by a dilute solu- Witnesses:

tion of sodium carbonate and drying the WLADYsKEI: STEFANOSKY, hereby obtained sodium salt. ALEXANDER FYLAKWICZ. 

